The only way the Democrats would be able to delay or block the cabinet appointments would be if 3 or more Republican senators can be convinced not to vote for the appointments. 

A simple majority (51 votes) in the senate is sufficient for the appointments to proceed, and that vote can't be filibustered. ([Source][1])


  [1]: https://www.washingtonpost.com/news/powerpost/wp/2016/11/18/president-trumps-cabinet-picks-are-likely-to-be-easily-confirmed-thats-because-of-senate-democrats/